Recently, thermoplastic resins have replaced conventional glass or metal materials in electric/electronic products, automobiles, construction materials, leisure products, and the like. The thermoplastic resins should satisfy requirements such as impact resistance, weather resistance, workability and high quality appearance.
Generally, when an acrylonitrile-butadiene-styrene resin (hereinafter, ABS resin) is used as the thermoplastic resin, π-bond of the butadiene-based rubbery polymer is stimulated by UV to be unfavorably decomposed, which can cause discoloring or cracking a product. Therefore, an acrylonitrile-styrene-acrylate resin (hereinafter, ASA resin) using an acryl-based rubbery polymer instead of the butadiene-based rubbery polymer is known as a substitute to solve the UV-decomposition problem since the acryl-based rubbery polymer has no π-bond. In addition, the ASA resin has merits of excellent formability, chemical resistance, thermal stability and the like and a lower specific gravity than glass or metal.
Meanwhile, recently, there is increased demand for an environmentally-friendly non-coated resin with a metal-like texture material capable of having a metallic paint-like appearance.
A thermoplastic resin composition can include metal particles to provide a metal-like texture as an alternative to a painted product. When the metal particles are added into the thermoplastic resin composition, however, impact resistance, weather resistance, and the like may be deteriorated, and the appearance of a molded product may be deteriorated when it is injection-molded, so the application thereof is limited.
U.S. Pat. No. 7,135,520 disclosed that the appearance is improved by using a mixture of milled glass fiber and chopped glass fiber. The appearance improvement effect, however, can be insufficient, and mechanical strength can be deteriorated.
Japanese Patent Laid-Open Publication No. 2001-262003 discloses the use of metal particles for the metal-like texture. A flow mark or a weld line, however, can form during injection molding.
Accordingly, there is a need for a thermoplastic resin composition that can be used, for example, as an exterior material, having a metal texture while maintaining impact resistance and weather resistance of the thermoplastic resin.